Aerospace 303 protectant! You can order online or sometimes find it in stores. I believe Camping World out by you stocks in there RV care section. It's great protectant that leaves a nice finish that is not overly glossy looking. It makes the dash like new again. There is very little if any cleaning agents in the 303 however so to clean you will need something else. For light cleaning and protectant all in one I've been using Optima leather protectant+, the + is the added cleaning agent. If I really need to clean the interior well I use Meguiars All purpose cleaner D101. I bought a gallon size and dilute to the proper ratio in different bottles for different areas of the car. I use a 10:1 ratio for the interior cleaning and a 4:1 ratio for the exterior, wheels, engine etc. There is also Meg APC+ D103, the difference is that the D103 is low foaming so it can be used in a carpet cleaning machine, is a bit stronger so ratios are slightly different and it has an orange sent to it. D103 is harder to find.
My interior cleaning goes like this if it's really dirty and needs a lot of attention.
1) Vacuum all the carpets, floor mats and seats,
2) using a microfiber, spray and wipe down all surfaces with Megs APC 10:1, including seats, doors and dash.
3) another clean microfiber and spray and wipe down all surfaces except screens with 303 protectant.
4) Spray Stoner's invisible glass onto a clean paper towel (I grab handfuls of the gas station ones) and wipe all windows. Don't spray the windows, spray the towels so you don't get over spray on the dash.
5) Done!
If it's not too dirty, I'll just use Optima Leather protectant plus and for a quick clean up Meguiars interior quick detailer.